A report is created in the Crystal Reports designer (Line Charts)

The x-axis on the chart has a large number of data labels, making it impossible to read them. I need to reduce the number of labels on the x-axis to make them legible.

How can Ilimit the number of labels on the x-axis?

the crystal report decisions website tells me to
goto the:

"Numeric Grid Axis & scales" properrties for the chart
(right click, Format Chart, Grid) then
Group axis, Labels

and check the box labelled "Use Manual Number of Groups"
then enter a number the the box below.

I need to enter 60, but an error message box appears;
"Invalid entry: You have to enter a value between 1 and 3"

do i need to download an update?
this error appears on;
Crystal Reports.Net and
Crystal Reports Verion 8

please help, i need help!
thanks,

Tom